52. Compare sexual and asexual reproduction Meiosis is not required The organism will “clone” itself through mitosis or budding No division of DNA Diploid-Diploid Bacteria Meiosis required Formation of egg and sperm Half if the genetic info (haploid) Egg and sperm will fuse to create zygote Genetic information will be different from the parents Combination

53. Diploid vs. Haploid “complete” set of genetic information Somatic cells (body cells) 2N “Half” of the genetic information usually found in the organism Gametes (egg and sperm) N

54. Fertilization – egg + sperm = zygote Zygote – fertilized egg and sperm (diploid) Cleavage – first few mitotic cell divisions after zygote is formed Morula – solid ball of cells after zygote begins to divide Blastula – fluid filled ball of cells Implantation – -blastocyst attaches to uterine wall Gastrulation – cells of blastocyst develop into 3 germ layers to form gastrula Embryo – implantation to 8 weeks Fetus – after 8 weeks

= unspecialized cells that have the potential to differentiate 55. Stem Cells = unspecialized cells that have the potential to differentiate Cell Differentiation = giving cells specific jobs. Begins with neurulation

57. The PLACENTA is a maternal-fetal organ which begins developing at implantation of the blastocyst Exchanges nutrients, gases, and waste products Image from: http://embryology.med.unsw.edu.au/Medicine/BGDlabplacenta.htm

58. The formation of 3 germ layers a. Endoderm Inner-most layer (digestive tract) b. Mesoderm Middle layer (internal organs) c. Ectoderm Outer-most layer (skin and nervous system) Images from: http://www.childrenscolorado.org/wellness/info/kids/21825.aspx; https://marketplace.secondlife.com/p/Beating-Anatomical-Heart-Animation-Sound/833619?id=833619&slug=Beating-Anatomical-Heart-Animation-Sound; http://www.rocketgirls.org/8-steps-for-beautiful-glowing-skin-cleanse.html; http://biologieprojekt2009.wordpress.com/von-der-zygote-zum-mehrzeller/; http://www.youtube.com/watch?v=UgT5rUQ9EmQ/;